The invention relates to sampled measurement data stream control, and particularly to a remote device and a system for an electrical network and a method for controlling sampled measurement data stream in an electrical network.
An electrical network is typically a very large entity comprising a very large number of measurement devices monitoring the state of the electrical network and trying to detect faults and deviations. Over time, large number of these faults and deviations occur in different parts of the electrical network and a very large number of devices detect these faults over a long period of time.
It also follows that in an electrical network, a specific fault is typically detected by several devices at the same time. This might be because a fault occurs in several locations at the same time, but more typically this is caused by several devices reacting to the same fault. These might be the devices of the same area or even devices from subsequent areas that react to the fault even though it doesn't actually happen inside their own area. This causes a multiplied amount of information to be transferred over the communication network 6 between the devices.
It is usual that most of the central supervision and control systems requiring measurement values from several different locations mostly use physical wiring. This means excessive amount of wiring if several locations are connected and creates high costs. Bus communication has been introduced to reduce the need for wiring, but the bus communication often ends up being a bottle neck resource due to the large amount of sampled measure values (or sampled measured values as referred to in IEC61850) that need to be sent from a plurality of senders simultaneously.
US 2014280712 discloses systems and methods for exchanging messages between devices in an electrical power generation and delivery system, and particularly transmitting messages included in a message stream that includes multiple redundant copies of the messages, and receiving an indication to confirm that at least one message of the message stream was received by an intended receiving device. US 2013205022 discloses a system and a method for energy management reporting, analysis, and billing system, wherein parameters of a commodity consumed at a customer location are measured with meters and the measured parameters are transmitted to a server in communication with the one or more meters by way of a communication network, whereby the server may be configured to receive the measured parameters from the one or more meters and store the parameters as log data. WO 2011121386 discloses a method for coordinated transfer of control in a substation system comprising IED or logical devices/servers using GOOSE messages with preconfigured data models with logical nodes containing one or more data objects including private data objects connected in the substation communication network, whereby an operation is handed over from one device of a hot-standby pair to the other, if the first device fails.
It is known to store information about a fault in a remote device of an electrical network when a fault is detected, inform central monitoring station or similar about the fault and then read the data from one or several remote devices to the central monitoring station at a suitable moment of time. However, information is then always got only after the incident and typically very late considering solving the problem.